Th nam 11 thang 11 nam 2010

* Neu ac iem chnh cua nc sach.Nc sach la nc trong suot, khong mau, khong mui, khong v, khong cha cac vi sinh vat hoac cac chat hoa tan co hai cho sc khoe con ngi.

* Neu ac iem chnh cua nc b o nhiem. - Nc b o nhiem la nc co mot trong cac dau hieu sau: co mau, co chat ban, co mui hoi, co cha cac vi sinh vat gay benh nhieu qua mc cho phep hoac cha cac chat hoa tan co hai cho sc khoe.

Th nam 11 thang 11 nam 2010 S/ 54

Hoat ong 1: Tm hieu mot so nguyen nhan lam nc b o nhiem. * Neu nguyen nhan lam nc b o nhiem trong moi hnh trang 54, 55 SGK.

Thao luanNhom 2

Hnh1: Nc thai t nha may khong qua x l xuong song lam nc song co mau en, ban.

Hnh 2: Ong nc sach b v, cac chat ban chui vao ong nc, nc sach b nhiem ban.

Hnh 3: Tau b am tren bien. Dau tran ra mat bien lam o nhiem nc bien.

Hnh 4: o rac, chat thai xuong song lam nc song b nhiem ban, boc mui hoi thoi.

Hnh 5: Bon phan hoa hoc cho rau lam o nhiem mach nc ngam.

Hnh 6: Phun thuoc tr sau cho lua gay o nhiem nc.

Hnh7: Kh thai khong qua x l t cac nha may thai ra ngoai gay o nhiem khong kh va o nhiem nc ma.

Hnh 8: Kh thai t cac nha may lam o nhiem nc ma. Chat thai nha may, bai rac, phan bon, thuoc tr sau lam o nhiem mach nc ngam.

Lien he en a phng mnh neu nguyen nhan lam o nhiem nc a phng.+ Do nc thai t cac chuong chan nuoi cua cac ho gia nh.+ Do o rac ban xuong song.+ Do nc thai t cac gia nh o xuong cong.+ Do khoi, kh thai t nha may.

Co rat nhieu viec lam cua con ngi gay o nhiem nguon nc. Nc rat quan trong oi vi i song con ngi, thc vat va ong vat, do o chung ta can han che nhng viec lam co the gay o nhiem nguon nc.

Hoat ong 2: Thao luan ve tac hai cua s o nhiem nc. ieu g se xay ra oi vi sc khoe cua con ngi khi nguon nc b o nhiem?

Thao luannhom 5

Nguon nc b o nhiem la moi trng tot e cac loai vi sinh vat sinh song nh: rong,reu, tao, bo gay, ruoi, muoi. . .chung phat trien va lan truyen cac loai benh dch nh ta, l, thng han, tieu chay, bai liet, viem gan, mat hot,..co ti 80%cac benh la do s dung nguon nc b o nhiem.

Tac hai cua viec s dung nguon nc b o nhiem: lan truyen nhieu benh, trong thc te c 100 ngi mac benh th co 80 ngi mac cac benh lien quan en nc. V vay chung ta phai han che nhng viec lam co the lam cho nc b o nhiem.

* Theo em, moi ngi dan chung ta can phai lam g e han che nguon nc b o nhiem?

* Hoc sinh oc muc ban can biet SGK/ 55